I have a 2007 dodge dakota 3.7L V6 4x4 transmission lost reverse over a year ago. I still have every other gear. Even changed the sensor that it was throwing code for. High pressure line sensor that's on the valve body. Still saying the same thing.
after so many miles it goes into limp mode.
VLP variable line pressure has to be cleared on all loops.
I bought a transmission out of a 2004 dodge dakota 3.7 4x4 was told transmission would work.
But is missing 2 wiring plugs on the 04 transmission that my 07 transmission has

 

A similar thing happened to my dakota which was the beginning of the end for me. The reverse clutch went bad and I had no reverse. The transmission guy said that all forward gears were absolutely perfect, he couldn't explain what caused my issue with just reverse.

After issues with the dealer and him blaming me for abusing my truck, I gave up, paid for the transmission repair and sold the dakota.

 

The auto trans matched with the 3rd-Gen 3.7 Dakotas is the 42RLE, and the 3rd Gen Dakota begins with the 2005 model year. However, according to Wikipedia, the 42RLE first arrived in the Dakotas beginning with model year 2004, which was the last year of the 2nd Gen Dakota.

It's always possible some sort of electronic difference exists between the version installed in the 2nd-Gen 2004 Dakota and the version installed in your 2007 3rd-Gen Dakota...